Fuel Cost Calculator — Free Online Trip Fuel Estimator

How to Use the Fuel Cost Calculator

1. Enter your trip distance: Type the one-way distance of your trip in miles into the Distance field. If you are planning a road trip, use a mapping application to find the exact mileage between your starting point and destination. For daily commutes, use the distance from home to work.
2. Enter your vehicle's MPG: Input your vehicle's fuel efficiency in miles per gallon. The EPA fuel economy rating can be found in your owner's manual, on the window sticker of new vehicles, or by searching your vehicle at fueleconomy.gov. For a more accurate real-world figure, divide the miles from your last full tank by the gallons it took to refill.
3. Enter the current gas price: Type the current price of gasoline per gallon in your area. Prices vary significantly by state and even by neighborhood, so check your local station or a fuel price comparison app for the most accurate figure. The calculator defaults to a common national average.
4. Toggle round trip if needed: If you need to account for the return journey, enable the Round Trip toggle. This automatically doubles your entered distance and calculates the total fuel cost for both directions. The results will reflect the complete journey including the return trip.

All results update in real time as you change any value. Experiment with different MPG values to compare vehicles, or adjust gas prices to see how price fluctuations affect your travel budget.

Fuel Cost Formula

Variables Explained

• Total Distance: The total number of miles for your trip. If round trip is enabled, this equals twice your entered distance. This is the total mileage your vehicle must cover, and it directly determines how much fuel you will consume.
• MPG (Miles Per Gallon): Your vehicle's fuel efficiency rating, representing how many miles you can drive on one gallon of gasoline. Higher MPG means better fuel economy and lower costs. Real-world MPG is typically 10% to 20% lower than EPA estimates due to driving conditions, weather, and driving habits.
• Price Per Gallon: The current cost of one gallon of gasoline at the pump. This varies by region, octane level, and market conditions. As of early 2026, the national average for regular unleaded gasoline in the United States hovers around $3.30 to $3.70 per gallon.
• Cost Per Mile: The derived cost of driving each mile, calculated by dividing total fuel cost by total distance. This metric is useful for comparing the operating costs of different vehicles or routes and for budgeting purposes.

Step-by-Step Example

Suppose you are planning a round trip from Dallas to Houston (about 240 miles one way) in an SUV that gets 22 MPG, with gas at $3.45 per gallon:

1. Calculate total distance (round trip): 240 x 2 = 480 miles
2. Calculate gallons needed: 480 / 22 = 21.82 gallons
3. Calculate total fuel cost: 21.82 x $3.45 = $75.28
4. Calculate cost per mile: $75.28 / 480 = $0.157 per mile

This round trip will consume about 21.8 gallons and cost approximately $75.28 in fuel alone. At roughly $0.16 per mile, you can quickly estimate costs for similar distances in the future.

Practical Examples

Example 1: Jennifer's Daily Commute

Jennifer drives 28 miles each way from her home in the suburbs to her office downtown. She drives a compact sedan that averages 32 MPG, and regular gas near her home costs $3.40 per gallon. Using the fuel cost calculator with round trip enabled:

• Total daily distance: 28 x 2 = 56 miles
• Gallons per day: 56 / 32 = 1.75 gallons
• Daily fuel cost: 1.75 x $3.40 = $5.95
• Monthly cost (22 working days): $5.95 x 22 = $130.90
• Annual commute cost: $130.90 x 12 = $1,570.80

Jennifer now budgets approximately $131 per month for her commute fuel. She also uses this data to compare the cost of driving versus taking public transit, which costs her $95 per month in her city.

Example 2: Marcus's Cross-Country Road Trip

Marcus is planning a one-way road trip from Los Angeles to New York City, a distance of approximately 2,790 miles. He drives a midsize SUV averaging 26 MPG and expects gas to average $3.55 per gallon across the states he will pass through:

• Gallons needed: 2,790 / 26 = 107.3 gallons
• Total fuel cost: 107.3 x $3.55 = $380.92
• Cost per mile: $380.92 / 2,790 = $0.137

Marcus budgets around $381 for fuel on his cross-country drive. He plans to fill up in states with lower gas taxes like Missouri and Oklahoma to save money along the way. With about 15 fill-ups needed, he can plan his stops accordingly.

Example 3: Rachel's Weekend Getaway

Rachel is taking a weekend trip from Chicago to a cabin in Michigan, about 180 miles each way. Her hybrid sedan gets 48 MPG and gas currently costs $3.60 per gallon. She enables the round trip toggle:

• Total distance: 180 x 2 = 360 miles
• Gallons needed: 360 / 48 = 7.5 gallons
• Total fuel cost: 7.5 x $3.60 = $27.00
• Cost per mile: $27.00 / 360 = $0.075

Rachel's hybrid makes the weekend getaway remarkably affordable at just $27 in fuel for the entire round trip. At $0.075 per mile, her fuel-efficient vehicle costs less than half of what a typical SUV would for the same journey.

Example 4: Tom's Pickup Truck Work Run

Tom uses his full-size pickup truck for work, hauling materials to job sites about 65 miles away. The loaded truck averages only 15 MPG, and diesel costs $4.10 per gallon. He calculates the round trip cost:

• Total distance: 65 x 2 = 130 miles
• Gallons needed: 130 / 15 = 8.67 gallons
• Total fuel cost: 8.67 x $4.10 = $35.55
• Cost per mile: $35.55 / 130 = $0.274

Tom factors the $35.55 fuel cost into his project bids. Over a month of 12 such trips, his fuel cost is $426.60. Understanding this cost per mile of $0.27 helps him set competitive but profitable pricing for his contracting business.

Fuel Cost Reference Table

Table assumes gas price of $3.50/gallon. Multiply values proportionally for different gas prices.

Tips and Complete Guide

Maximizing Fuel Economy on the Road

Getting the best possible fuel economy saves money on every trip. Maintain steady speeds and use cruise control on highways to avoid the fuel waste of constant acceleration and deceleration. Keep your tires inflated to the manufacturer's recommended pressure, as underinflated tires can reduce fuel economy by 3% or more. Remove unnecessary weight from your vehicle since every extra 100 pounds reduces MPG by about 1%. Avoid excessive idling, which wastes a quarter to a half gallon of fuel per hour. Use the recommended grade of motor oil and keep up with regular maintenance, particularly air filter replacements and spark plug changes, which help your engine run at peak efficiency.

Planning Routes to Save on Fuel

Strategic route planning can significantly reduce fuel costs. Highway driving at consistent speeds is generally more fuel-efficient than stop-and-go city driving, even if the highway route is slightly longer in distance. Use navigation apps that factor in current traffic conditions to avoid congestion, which destroys fuel economy. When possible, combine multiple errands into a single trip to reduce total miles driven. Plan your fill-ups in advance by checking gas prices along your route, as prices can vary by $0.50 or more per gallon between states. States with lower fuel taxes like Missouri, Mississippi, and Oklahoma consistently have cheaper gas than high-tax states like California and Pennsylvania.

Understanding Real-World MPG vs EPA Ratings

The EPA fuel economy ratings displayed on new vehicle window stickers are determined through standardized lab testing and represent idealized conditions. In real-world driving, most vehicles achieve 10% to 20% lower MPG than the EPA estimate. Factors that reduce real-world efficiency include aggressive driving habits, short trips where the engine never fully warms up, hilly terrain, strong headwinds, hot weather requiring air conditioning, and cold weather that increases engine warm-up time. To calculate your actual MPG, fill your tank completely, reset your trip odometer, drive normally until you need fuel again, fill up, and divide the miles driven by gallons purchased. Use your real-world MPG in our gas mileage calculator for the most accurate trip cost estimates.

Common Mistakes to Avoid

• Using EPA MPG instead of real-world MPG: EPA ratings are optimistic. Always use your actual measured fuel economy for accurate cost estimates, especially for long trips where small per-mile differences add up significantly.
• Forgetting to account for elevation changes: Mountainous routes consume substantially more fuel than flat terrain. If your trip includes significant elevation changes, reduce your expected MPG by 10% to 25% for those segments.
• Ignoring the cost of idling in traffic: Extended traffic jams and city driving can reduce effective MPG by 30% to 50% compared to highway driving. If your route includes heavy traffic, adjust your MPG estimate downward.
• Not budgeting for gas price variation: Gas prices can vary dramatically along a route, especially when crossing state lines. Budget for higher-than-average prices to avoid being caught short.
• Overlooking vehicle load weight: Carrying heavy cargo, towing a trailer, or having a full car of passengers all reduce fuel economy. A fully loaded roof rack alone can decrease MPG by 2% to 8% on highways due to increased aerodynamic drag.

Frequently Asked Questions